DETERMINATION OF SORPTION CHARACTERISTICS OF MATERIALS FOR THE TRANSFORMATION OF LIQUID RADIOACTIVE WASTE INTO A NON-FLOWABLE STATE

In 1999, the Government of the Republic of Kazakhstan adopted a decision to decommission the BN-350 reactor facility (RF). The decommissioning concept consists of three main stages: the first stage involves bringing the reactor to a safe condition, the second stage ensures storage for approximately 50 years, and the third stage includes the dismantling of buildings and structures, followed by the disposal of the resulting radioactive waste. During the first stage of decommissioning, the placement of spent nuclear fuel for long-term storage, handling of heat-transfer media, liquid and solid radioactive waste, as well as preparation of buildings and structures for safe storage are planned. Liquid radioactive waste (LRW) accumulated during the reactor’s operational period is currently stored in specially designated containers. Due to the long service life of these containers and the potential risk of their integrity being compromised, developing effective methods for converting LRW into a non-liquid (solid or gel-like) form is an urgent scientific and technical task. Such methods allow for the prevention of radioactive substance release into the environment even under potential accident conditions. One of the promising approaches to LRW immobilization is the use of sorbent materials, which efficiently isolate liquid waste and limit the migration of radionuclides [1–3].

This study presents a methodology for determining the sorption properties of various materials offered by manufacturers for converting liquid radioactive waste into a non-liquid form. The results of the investigation of the sorption characteristics of a number of industrial and experimental sorbent samples are provided, and their effectiveness was evaluated during interaction with model LRW solutions.

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